1. Technical Field of the Invention
The present invention relates to a hydrogen gas generator.
2. Description of the Related Art
An inhalation apparatus for hydrogen gas is known, which is configured such that an air mixer is attached to a part of a conduit pipe from a hydrogen gas generator to a nasal cavity cannula thereby to adjust the concentration of hydrogen gas to be supplied into the body (Patent Document 1: JP 2009-5881 A). In this inhalation apparatus for hydrogen gas, a sensor for detecting the hydrogen gas concentration is provided in the gas flow channel between the air mixer and the nasal cavity cannula, and the hydrogen gas concentration detected by the sensor is fed back to a controller for controlling the value of an electrolytic current to be applied to the hydrogen gas generator.
Patent Document 1: JP 2009-5881 A
When this kind of hydrogen gas generator is used for a patient to inhale hydrogen gas, it may be preferred that the generator can display the hydrogen gas concentration to allow the patient or an operator to confirm whether the hydrogen gas concentration has an appropriate value.
Examples of a commonly-known sensor for detecting the hydrogen gas concentration include a sensor device using a hydrogen absorbing alloy or the like of which the electric resistance value reversibly varies due to selective absorption of hydrogen gas (JP 2005-256028 A) and a sensor device using a thin film layer of which the resistance value reversibly varies due to contact with a sample gas that is oxidized and decomposed through a photocatalyst layer utilizing a photocatalytic action (JP 2005-214933 A). However, if such kind of sensor device is used as the sensor for detecting the hydrogen gas concentration in the above apparatus of the prior art, the lifetime of the sensor device will be shortened due to the moisture contained in the hydrogen gas, which may be problematic.
Therefore, an object of the present invention is to provide a hydrogen gas generator that can accurately present the concentration of generated hydrogen gas without using a hydrogen gas concentration sensor which is weak against moisture.